The concept of the 15-minute city has recently sparked one of the most debated topics, attracting both strong supporters and vocal critics. Among them, some warn the risk that the creation of fully walkable settlements, equipped with sufficient amenities to make them functionally autonomous from the rest of the city, could lead to segregative effects, so as to result in the formation of isolated urban areas, increasing the risks of social segmentation and reducing diversity in the social fabric. Such an objection necessitates broadening the perspective by shifting the discussion from the intrinsic features of the neighbourhood to the question of its location within the overall system, so as to ensure that the local network of interactions and movements is properly integrated within the broader set of relationships at a global scale. Regarding the connections between different parts of a system, recent studies highlighted the strategic importance of spatial elements that act as crucial bridges between its various subsystems. These elements were defined ‘weak ties’ because of their strong analogy with the components identified by Mark Granovetter in his seminal theory. Despite their weak local connectivity and global centrality, they play a fundamental role in the system as a whole, in that they bind together its different parts. This paper, after addressing the transferral of weak ties theory into a spatial logic, aims at discussing their bridging capacity as an essential requirement for the location of 15 min neighborhoods, preventing the risk of their isolation and compartmentalization.